A hard Brexit is now a realistic prospect and firms here need to do more to prepare for it, Central Bank deputy governor Ed Sibley said in speech in Dublin.

He warned that there are "direct and material impacts" for existing financial services firms operating in Ireland, especially those who have direct exposure to the UK.

“It is entirely plausible that there will be a ‘hard’ Brexit, with no transition period. Much more work needs to be done to prepare for this plausible scenario, particularly in the insurance sector,” he said.

The Central Bank’s most senior and experienced experts are now working on Brexit related areas, he said, including to authorise and supervise new entrants or changes to existing firms.

For Ireland, the “loss of the UK voice” at the European level in relation to regulation is “particularly negative,” he said.

In his first major speech since being named as deputy governor, Ed Sibley warned against any move to dilute regulations toughened after the financial crisis.

Across all sectors he said it was obvious that there is still "much work needed" and strong evidence that the level of cultural change has been insufficient.